Girolamo Cardano, an Italian physician, was born Sep. 24, 1501. Cardano led a tumultuous life in Milan and Bologna, constantly involved in scrapes involving gambling or professional rivalry. His older son, whom he cherished, was convicted and executed for poisoning his wife. Cardano himself was briefly imprisoned on suspicion of heresy. Yet in spite of his woes, Cardano became one of the most sought-after physicians in Italy, second perhaps only to Andreas Vesalius, even being invited to Scotland to cure an archbishop there. That he lived to be almost 75 is quite astonishing, as he himself confesses in his delightful Autobiography.

Like many physicians in the Renaissance, Cardano strongly believed in the importance of astrology for practicing medicine, and he wrote several astrological treatises in the 1540s. The Libelli quinque (Five Books, 1547) is especially interesting because it contains the genitures of important Renaissance individuals, including several scientists (a geniture, a specific kind of horoscope, shows the positions of the planets and signs of the zodiac at the moment of birth). We see here the genitures of the great pre-Copernican astronomer Regiomontanus (see second image above), the revolutionary anatomist Vesalius (third image), and the geometer-artist-engraver, Albrecht Dürer (fourth image). There is no horoscope of Cardano in the book, but he does include a portrait of himself on the verso of the title page (first image).

Dr. William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor, Department of History, University of Missouri-Kansas City. Comments or corrections are welcome; please direct to